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Tesi sul tema "Amplifiers"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 1 agosto 2024

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1

Shao, Jin. "Advanced Power Amplifiers Design for Modern Wireless Communication." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc804973/.

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Modern wireless communication systems use spectrally efficient modulation schemes to reach high data rate transmission. These schemes are generally involved with signals with high peak-to-average power ratio (PAPR). Moreover, the development of next generation wireless communication systems requires the power amplifiers to operate over a wide frequency band or multiple frequency bands to support different applications. These wide-band and multi-band solutions will lead to reductions in both the size and cost of the whole system. This dissertation presents several advanced power amplifier solutions to provide wide-band and multi-band operations with efficiency improvement at power back-offs.

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2

Hur, Joonhoi. "A highly linear and efficient out-phasing transmitter for multi-band, multi-mode applications." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/42823.

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There have been many efforts to improve efficiency of transmitter while meeting stringent linearity requirement of modern communication system. Among the technology to enhance efficiency of linear transmitter, the out-phasing technologies, also called the linear amplification with nonlinear components (LINC), is considered as a promising technology. LINC has been studied long times, since it provides excellent linearity with high efficiency by allowing adopt high efficient switch-mode power amplifiers. However, The LINC transmitter has some technical challenges: linearity degradation due to amplitude and phase mismatches, efficiency degradation due to poor combining efficiency, and narrow frequency bandwidth due to output matching network of switching power amplifier. In this thesis, some state-of-the-art techniques for solving the problems of LINC transmitters are presented. An unbalanced phase calibration technique compensates amplitude/phase mismatches between two parallel paths in the LINC system, and multi-level LINC (MLINC) and an uneven multi-level LINC (UMLINC) structure improve the overall power efficiency. And the reconfigurable Class-D switching PA enables multi-band operation with high efficiency and good linearity. With these techniques, the new multi-band out-phasing transmitter improves the efficiency without sacrificing the linearity performance.

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3

Kim, Moonil. "Grid amplifiers." Diss., Pasadena, Calif. : California Institute of Technology, 1993. http://resolver.caltech.edu/CaltechETD:etd-08292007-104142.

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4

Talli, Giuseppe. "Amplified spontaneous emission and gain dynamics in semiconductor optical amplifiers." Thesis, University of Essex, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397730.

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5

Lee, Ockgoo. "High efficiency switching CMOS power amplifiers for wireless communications." Diss., Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/37145.

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High-efficiency performance is one of the most important requirements of power amplifiers (PAs) for wireless applications. However, the design of highly efficient CMOS PAs for watt-level applications is a challenging task. This dissertation focuses on the development of the design method for highly efficient CMOS PAs to overcome the fundamental difficulties presented by CMOS technology. In this dissertation, the design method and analysis for a high-power and highefficiency class-E CMOS PA with a fully integrated transformer have been presented. This work is the first effort to set up a comprehensive design methodology for a fully integrated class-E CMOS PA including effects of an integrated transformer, which is very crucial for watt-level power applications. In addition, to improve efficiency of cascode class-E CMOS PAs, a charging acceleration technique is developed. The method accelerates a charging speed to turn off the common-gate device in the off-state, thus reducing the power loss. To demonstrate the proposed cascode class-E PA, a prototype CMOS PA was implemented in a 0.18-μm CMOS process. Measurements show an improvement of approximately 6% in the power added efficiency. The proposed cascode class-E PA structure is suitable for the design of high-efficiency class-E PAs while it reduces the voltage stress across the device.

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6

Kunarajah, Enoch Arumaishanth. "Distributed Raman amplifiers." Thesis, University of Essex, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399979.

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7

Barradas, Filipe Miguel Esturrenho. "RF parametric amplifiers." Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/10198.

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Mestrado em Engenharia Electrónica e Telecomunicações<br>Recentemente tem-se feito um esforço no sentido de aumentar a eficiência em aplicadores de RF, no entanto, o transístor é um dispositivo intrinsecamente ineficiente. Utilizando amplificadores paramétricos pode-se teoricamente chegar a 100% de eficiência mesmo operando em modo linear. A razão desta elevada eficiência é o dispositivo activo utilizado, já que os amplificadores paramétricos utilizam uma reactância controlada, que não consome potência. Esta mudança de elemento activo modifica completamente o princípio de funcionamento dos amplificadores. Neste trabalho este tipo de amplificação é estudado, relações e transformações conhecidas são examinadas primeiro para obter propriedades limite gerais. Depois é feita análise de pequeno sinal para se obterem outras características importantes. Finalmente, um novo modelo de grande sinal é derivado e apresentado. Este modelo é capaz de prever algumas características do amplificador, tal como o AM/AM. Utilizando o modelo de grande sinal apresentado projecta-se um amplificador, sendo este posteriormente simulado.<br>In recent years a significant effort has been made towards efficiency increase in RF amplifiers. The transistor is, however, an intrinsically inefficient device. Parametric amplification can theoretically be 100% efficient even operating in linear mode. The reason behind this efficiency is the active device. These amplifiers forget the transistor to use a controlled reactance, which cannot consume power. This switch in active element changes the whole principle of operation of the amplifiers. In this work this type of amplification is studied. Known relations and transformations are first examined to obtain general limit properties of the used elements. Then small-signal analysis is performed to obtain other important characteristics. Finally, a novel large signal model is developed and presented. This model is capable of accurately predicting the non-linear responses of the amplifier, such as the AM/AM. Using the presented large-signal model, an amplifier is designed and simulated.

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8

Al, Tanany Ahmed. "A Study of Switched Mode Power Amplifiers using LDMOS." Thesis, University of Gävle, Department of Technology and Built Environment, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-701.

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<p>This work focuses on different kinds of Switch Mode Power Amplifiers (SMPAs) using LDMOS technologies. It involves a literature study of different SMPA concepts. Choosing the suitable class that achieves the high efficiency was the base stone of this</p><p>work. A push-pull class J power amplifier (PA) was designed with an integrated LC resonator inside the package using the bondwires and die capacitances. Analysis and motivation of the chosen class is included. Designing the suitable Input/Output printed circuit board (PCB) external circuits (i.e.; BALUN circuit, Matching network and DC</p><p>bias network) was part of the work. This work is done by ADS simulation and showed a simulated result of about 70% drain efficiency for 34 W output power and 16 dB gain at 2.14 GHz. Study of the losses in each part of the design elements is also included.</p><p>Another design at lower frequency (i.e.; at 0.94 GHz) was also simulated and compared to the previous design. The drain efficiency was 83% for 32 W output power and 15.4 dB Gain.</p>

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9

Gray, Blake Raymond. "Design of RF and microwave parametric amplifiers and power upconverters." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43613.

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The objective of this research is to develop, characterize, and demonstrate novel parametric architectures capable of wideband operation while maintaining high gain and stability. To begin the study, phase-incoherent upconverting parametric amplifiers will be explored by first developing a set of analytical models describing their achievable gain and efficiency. These models will provide a set of design tools to optimize and evaluate prototype circuit boards. The prototype boards will then be used to demonstrate their achievable gain, bandwidth, efficiency, and stability. Further investigation of the analytical models and data collected from the prototype boards will conclude bandwidth and gain limitations and end the investigation into phase-incoherent upconverting parametric amplifiers in lieu of negative-resistance parametric amplifiers. Traditionally, there were two versions of negative-resistance parametric amplifiers available: degenerate and non-degenerate. Both modes of operation are considered single-frequency amplifiers because both the input and output frequencies occur at the source frequency. Degenerate parametric amplifiers offer more power gain than their non-degenerate counterpart and do not require additional circuitry for idler currents. As a result, a phase-coherent degenerate parametric amplifier printed circuit board prototype will be built to investigate achievable gain, bandwidth, and stability. Analytical models will be developed to describe the gain and efficiency of phase-coherent degenerate parametric amplifiers. The presence of a negative resistance suggests the possibility of instability under certain operating conditions, therefore, an in-depth stability study of phase-coherent degenerate parametric amplifiers will be performed. The observation of upconversion gain in phase-coherent degenerate parametric amplifiers will spark investigation into a previously unknown parametric architecture: phase-coherent upconverting parametric amplifiers. Using the phase-coherent degenerate parametric amplifier prototype board, stable phase-coherent upconversion with gain will be demonstrated from the source input frequency to its third harmonic. An analytical model describing the large-signal transducer gain of phase-coherent upconverting parametric amplifiers from the first to the third harmonic of the source input will be derived and validated using the prototype board and simulations.

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10

Gordienko, Vladimir. "Broadband fibre parametric amplifiers." Thesis, Aston University, 2018. http://publications.aston.ac.uk/37690/.

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This thesis explores the broadband fibre optical parametric amplifiers (FOPAs) to develop the FOPA ability to provide broadband amplification anywhere in the low-loss transmission window and to make FOPA an enabling technology for future ultra-wide bandwidth high-speed optical communications. A number of techniques have been implemented to demonstrate an exceptionally wide and flat FOPA gain of 10.5±0.5 dB over 102 nm bandwidth on a single side of the FOPA pump. A flat gain spectrum is targeted here because FOPA is prone to large gain variation which has a particularly strong negative impact on amplified signals in FOPA. The FOPA dependence on gain fibre length, pump wavelength and pump power has been experimentally investigated. The parametric gain bandwidth enhancement by a forward Raman gain invoked by the same pump has been demonstrated. Gain spectrum shaping by pump polarisation tuning has been explored and has allowed for a significant gain spectrum flatness improvement. A concept of cascading low gain stages has been introduced as a way to achieve a high gain with low variation across a wide bandwidth. It is envisaged that gain of ~20±1.5 dB over >100 nm can be achieved using this approach. Additionally, a reliance of the FOPA on Erbium doped fibre amplifiers (EDFAs) for pump amplification, which restricts the FOPA operating range, has been addressed by demonstrating a high pump power (>1 W) EDFA-free FOPA for the first time. In this experiment a Raman amplification was used instead of an EDFA to amplify the FOPA pump and thus to grant a required flexibility for FOPA operation anywhere in the low-loss transmission window. In summary, this thesis has demonstrated the FOPA ability to provide an ultra-wide amplification and has highlighted a way towards obtaining an optical gain in arbitrary spectral regions.

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11

Foo, Sik Heng. "Statistical properties of filtered amplified spontaneous emission noise of erbium-doped fiber amplifiers." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0019/MQ47029.pdf.

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12

Kim, Hyun-Woong. "CMOS RF transmitter front-end module for high-power mobile applications." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/47592.

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With the explosive growth of the wireless market, the demand for low-cost and highly-integrated radio frequency (RF) transceiver has been increased. Keeping up with this trend, complimentary metal-oxide-semiconductor (CMOS) has been spotlighted by virtue of its superior characteristics. However, there are challenges in achieving this goal, especially designing the transmitter portion. The objective of this research is to demonstrate the feasibility of fully integrated CMOS transmitter module which includes power amplifier (PA) and transmit/receive (T/R) switch by compensating for the intrinsic drawbacks of CMOS technology. As an effort to overcome the challenges, the high-power handling T/R switches are introduced as the first part of this dissertation. The proposed differential switch topology and feed-forward capacitor helps reducing the voltage stress over the switch devices, enabling a linear power transmission. With the high-power T/R switches, a new transmitter front-end topology - differential PA and T/R switch topology with the multi-section PA output matching network - is also proposed. The multi-stage PA output matching network assists to relieve the voltage stress over the switch device even more, by providing a low switch operating impedance. By analyzing the power performance and efficiency of entire transmitter module, design methodology for the high-power handling and efficient transmitter module is established. Finally, the research in this dissertation provides low-cost, high-power handling, and efficient CMOS RF transmitter module for wireless applications.

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13

Mishra, Chinmaya. "Design and implementation of low power multistage amplifiers and high frequency distributed amplifiers." Texas A&M University, 2004. http://hdl.handle.net/1969.1/2775.

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The advancement in integrated circuit (IC) technology has resulted in scaling down of device sizes and supply voltages without proportionally scaling down the threshold voltage of the MOS transistor. This, coupled with the increasing demand for low power, portable, battery-operated electronic devices, like mobile phones, and laptops provides the impetus for further research towards achieving higher integration on chip and low power consumption. High gain, wide bandwidth amplifiers driving large capacitive loads serve as error amplifiers in low-voltage low drop out regulators in portable devices. This demands low power, low area, and frequency-compensated multistage amplifiers capable of driving large capacitive loads. The first part of the research proposes two power and area efficient frequency compensation schemes: Single Miller Capacitor Compensation (SMC) and Single Miller Capacitor Feedforward Compensation (SMFFC), for multistage amplifiers driving large capacitive loads. The designs have been implemented in a 0.5??m CMOS process. Experimental results show that the SMC and SMFFC amplifiers achieve gain-bandwidth products of 4.6MHz and 9MHz, respectively, when driving a load of 25Kδ/120pF. Each amplifier operates from a ??1V supply, dissipates less than 0.42mW of power and occupies less than 0.02mm2 of silicon area. The inception of the latest IEEE standard like IEEE 802.16 wireless metropolitan area network (WMAN) for 10 -66 GHz range demands wide band amplifiers operating at high frequencies to serve as front-end circuits (e.g. low noise amplifier) in such receiver architectures. Devices used in cascade (multistage amplifiers) can be used to increase the gain but it is achieved at an expense of bandwidth. Distributing the capacitance associated with the input and the output of the device over a ladder structure (which is periodic), rather than considering it to be lumped can achieve an extension of bandwidth without sacrificing gain. This concept which is also known as distributed amplification has been explored in the second part of the research. This work proposes certain guidelines for the design of distributed low noise amplifiers operating at very high frequencies. Noise analysis of the distributed amplifier with real transmission lines is introduced. The analysis for gain and noise figure is verified with simulation results from a 5-stage distributed amplifier implemented in a 0.18??m CMOS process.

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14

Cartwright, Justin Adam. "A novel technique for harmonic cancellation in class D amplifiers a thesis presented to the faculty of the Graduate School, Tennessee Technological University /." Click to access online, 2009. http://proquest.umi.com/pqdweb?index=2&did=1759989201&SrchMode=1&sid=1&Fmt=6&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1250263495&clientId=28564.

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15

Fedorenko, Pavlo. "Phase distortion in envelope elimination and restoration radio frequency power amplifiers." Diss., Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/34822.

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The objective of this research is to analyze and improve linearity of envelope elimination and restoration (EER) radio frequency (RF) power amplifiers. Envelope elimination and restoration was compared to other efficiency enhancement techniques and determined to likely be the most suitable solution for implementation of multimode, multiband portable RF transmitters. Distortion, stemming from dynamic power-supply modulation of RF transistors in EER RF power amplifiers was identified as one of the key challenges to the development of commercially viable EER transmitters. This dissertation presents a study of phase distortion in RF power amplifiers (PAs) with emphasis on identification of the origins of phase distortion in EER RF power amplifiers. Circuit-level techniques for distortion mitigation are also presented. Memory effects in conventional power amplifiers are investigated through the accurate measurement and analysis of phase asymmetry of out-of-band distortion components. Novel physically-based power amplifier model is developed for attributing measured memory effects to their physical origin. The amount of linearity correction, obtained through pre-distortion for a particular RF power amplifier, is then correlated to the behavior of the memory effects in the corresponding PA. Heterojunction field-effect transistor and heterojunction bipolar transistor amplifiers are used for investigation of voltage-dependent phase distortion in handset EER RF PAs. The distortion is found to stem from vector addition of signals, generated in nonlinear circuit elements of the PA. Specifically, nonlinear base-collector capacitance and downconversion of distortion components from second harmonic frequency are found to be the dominant sources of phase distortion. Shorting of second harmonic is proposed as a way to reduce the distortion contribution of the downconverted signal. Phase distortion is reduced by 50%, however a slight degradation in the amplitude distortion is observed. Push-pull architecture is proposed for EER RF power amplifiers to cancel distortion components, generated in the nonlinear base-collector capacitance. Push-pull implementation enables a 67% reduction in phase distortion, accompanied by a 1-2 dB reduction in amplitude distortion in EER RF power amplifiers. This work, combined with other studies in the field, will help advance the development of multimode, multiband portable RF transmitters, based on the envelope elimination and restoration architecture.

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16

Enz, Christian C. Enz Christian Charles Enz Christian Charles Enz Christian Charles. "High precision CMOS micropower amplifiers /." [S.l.] : [s.n.], 1989. http://library.epfl.ch/theses/?nr=802.

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17

Banerjee, Gaurab. "Desensitized CMOS low noise amplifiers /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/6014.

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18

Bell, Patrick J. "MEMS-reconfigurable microwave power amplifiers." Diss., Connect to online resource, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3219036.

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19

Lewis, Steffan A. E. "Fibre Raman amplifiers for telecommunications." Thesis, Imperial College London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288385.

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20

Banyamin, Ben Yovel. "Cascaded single stage distributed amplifiers." Thesis, Brunel University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311244.

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21

Klele, Anthony G. "Noise analysis for analog amplifiers." Honors in the Major Thesis, University of Central Florida, 1993. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/119.

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This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucf.edu/Systems/DigitalInitiatives/DigitalCollections/InternetDistributionConsentAgreementForm.pdf You may also contact the project coordinator, Kerri Bottorff, at kerri.bottorff@ucf.edu for more information.<br>Bachelors<br>Engineering<br>Electrical Engineering

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22

Toumazou, C. "Universal current-mode analogue amplifiers." Thesis, Oxford Brookes University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372854.

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23

Mander, Gillian Linda. "Quantum theory of laser amplifiers." Thesis, University of Essex, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.290741.

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24

Rayanakorn, Surapap. "Design of micropower operational amplifiers." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/37079.

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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.<br>Includes bibliographical references (p. 149-151).<br>The operational amplifier is a fundamental building block for electronic devices and systems. The advancement of modern electronic technology has been setting more performance demand on the underlying integrated circuits including the operational amplifier. Reduction in power consumption and improvement in speed are some of the most important requirements. To address these concerns, this thesis presents a design of micropower Class AB operational amplifiers which has the ratio of gain bandwidth product to supply current higher than that of an existing IC. The design is in a 0.6pxm CMOS process. The input stage of the design has the folded-cascode architecture that allows the input common-mode range down to negative supply voltage. The Class AB output stage swings rail-to-rail and has the ratio of maximum current to quiescent current greater than 100. The bias cell of the operational amplifier is designed to consume only 6% of the total supply current. The thesis concludes the operational amplifier design with two frequency compensation options.<br>(cont.) The one with simple Miller compensation has a unity gain frequency of 360kHz with 61.5 degrees of phase margin at 100pF load while consuming 20[mu]A supply current. The other with the hybrid of simple Miller compensation and cascode compensation offers an improved unity gain frequency of 590kHz at the same loading and power condition.<br>by Surapap Rayanakorn.<br>M.Eng.

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25

Reilly, Mark Alexander. "Integrated polymer waveguide optical amplifiers." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614010.

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26

Zhu, Yanjun. "Novel fibre lasers and amplifiers." Thesis, King's College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.392685.

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27

Cao, Qiusheng. "Planar waveguide CO2 laser amplifiers." Thesis, Heriot-Watt University, 2000. http://hdl.handle.net/10399/1224.

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28

Mears, Robert Joseph. "Optical fibre lasers and amplifiers." Thesis, University of Southampton, 1987. https://eprints.soton.ac.uk/396453/.

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This thesis describes the development and characterisation of single-mode optical fibre lasers and amplifiers. Although the fibre laser configuration was first employed over twenty years ago, its application to conventional optical fibre technology has not been demonstrated previously. The new devices are based on single-mode fibres doped with rare-earth ions, notably neodymium and erbium. The combination of strong absorption bands, long fluorescence lifetimes; low fibre losses in the infra-red and small fibre cores have made possible very low threshold and efficient fibre lasers. Experiments on the tunability, output spectra and pulsed operation of these devices are described. A number of world firsts, including the Lowest, threshold and widest tuning range of a doped glass laser, and the efficient CW operation of an erbium-doped three level laser, have been achieved. High-gain amplification at 1.54µm, the preferred wavelength for optical communication, has also been demonstrated. The results have been modelled by adapting conventional laser theory to the single-mode fibre configuration, and some simple design criteria are considered.

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29

Mutha, Shashank. "Adaptive Linearization of Power Amplifiers." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1244049195.

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30

Wen, Pengyue. "Vertical cavity semiconductor optical amplifiers /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2002. http://wwwlib.umi.com/cr/ucsd/fullcit?p3070991.

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31

Wan, Quan. "Design of High Performance Amplifiers." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/294044.

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This dissertation presents circuit techniques for designing high performance amplifiers. In low power design, the range of common mode input signal shrinks due to reduced power supply voltage. In addition, due to reduced bias current, noise density rises. The reduced input signal range and raised noise floor severely degrade system dynamic range. A novel rail to rail input circuit is presented. The proposed circuit has advantages over conventional circuits in term of noise and power consumption. Moreover, due to reduced bias current, low power amplifiers typically have lower bandwidth and slew rate, which limits their dynamic performance. The bandwidth is further reduced at high gain settings because of the constant gain bandwidth product. A novel self-adaptive compensation technique to extend small signal bandwidth and improve slew behavior is presented. If an amplifier needs to drive various capacitive and/or resistive loads, parallel Miller compensation is the most power efficient frequency compensation scheme. However, the frequency response of parallel Miller compensation is complicated and no thorough analysis on frequency response has been given in literatures. To illustrate the connection between poles/zeros and each individual circuit component, we use a design oriented approach to derive transfer functions for various load conditions. With these transfer functions, circuit designers can optimize their design accordingly. As a case study, a low power precision instrumentation amplifier is designed. Compared to low power instrumentation amplifiers on the market or reported in literature, it can save at least 40% power, meanwhile offer higher bandwidth and faster slew rate at typical gain settings. Many challenges also exist in designing high voltage amplifiers. To achieve low cost and high performance, a novel topology of a high voltage current sensing amplifier is proposed. With this topology, major portion of amplifiers can be designed with low voltage, for instance, 5 V, devices, and only a limited amount of LDMOS are required to stand off high voltage. This topology does not have high noise gain as conventional solutions have. The same principle can be used for other high voltage amplifiers. A prototype chip is fabricated. The amplifier functions as expected. Test results are presented.

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32

An, Kyu Hwan. "CMOS RF power amplifiers for mobile wireless communications." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31717.

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Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2010.<br>Committee Chair: Laskar, Joy; Committee Member: Cressler, John; Committee Member: Kohl, Paul; Committee Member: Kornegay, Kevin; Committee Member: Tentzeris, Emmanouil. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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33

Jang, Haedong. "NONLINEAR EMBEDDING FOR HIGH EFFICIENCY RF POWER AMPLIFIER DESIGN AND APPLICATION TO GENERALIZED ASYMMETRIC DOHERTY AMPLIFIERS." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1406269587.

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34

Grantham, Clayton Bruce 1955. "A PARAMETRIC STUDY AND REDESIGN OF THE BLAUSCHILD HIGH SPEED INSTRUMENTATION AMPLIFIER ARCHITECTURE." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276494.

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This work contains the analysis and redesign of a translinear circuit. This circuit appeared in the article by Robert Blauschild. The Blauschild circuit was analyzed on H-SPICE, a VAX computer circuit analysis program, with Burr-Brown Integrated Circuit Process 30 models. Circuit improvement to input voltage to current converter stage and circuit simplification of the output stage were implemented and simulated in the redesign. The results of the two simulations were compared, which showed that the improvements were valid and useful. Going through this redesign cycle of circuit analysis, computer simulation and bread-boarding served as an actual design engineering application with a real problem, solution, and result scenarios.

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35

Willstedt, Alexander. "Absolutely amplified : A corpus study of amplifiers, their usage and collocations in two different corpora." Thesis, Linnéuniversitetet, Institutionen för språk (SPR), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-45539.

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The purpose of this study is to investigate the usage and frequencies of amplifiers in the English language and whether there are differences in usage, collocations and in gender. The material used is the Swedish-English Corpus (SWENC), a collection of Swedish native speaking journalists writing in English, and the Corpus of American Soaps (SOAP), a collection of American soap opera scripts. The size of the two corpora is quite different and therefore the number of tokens varies largely, but by using normalization, the frequencies have been compared. The results show differences in frequency and collocations between the different corpora and the conclusion drawn from this study is that there in fact are some amplifier differences when it comes to gender and collocations. KEYWORDS: adverbs, amplifiers, collocations, corpus-studies, gendered language, linguistics, normalization

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36

Schmid, Robert L. "Design of a reconfigurable low-noise amplifier in a silicon-germanium process for radar applications." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/47642.

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This thesis describes a unique approach of turning on and off transistor cores to reconfigure low-noise amplifiers. A small footprint single-pole, single-throw switch is optimized for low insertion loss and high isolation. A narrowband (non-switchable) LNA is developed as a basis of comparison for reconfigurable designs. The optimized switch is incorporated into different switchable transistor core architectures. These architectures are investigated to determine their ability to reconfigure amplifier performance. One switchable transistor core topology is integrated into a cascode LNA design. An in depth stability analysis employing the S-probe technique is used to help improve the reliability of the cascode design. In addition, a single-pole, double-throw transmit/receive switch, as well as a deserializer are developed to help support the LNA block in a reconfigurable phased-array radar system. This type of flexible radar design is very beneficial in challenging electromagnetic environments.

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37

Thipparapu, Naresh Kumar. "Development of bi-doped fibre amplifiers and lasers & broadband Er-doped multi-element fibre amplifiers." Thesis, University of Southampton, 2018. https://eprints.soton.ac.uk/423478/.

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The demand for fibre optic communication is continuously increasing over the years. This is due to the increased accessibility to the World Wide Web using internet of things. The capacity of current fibre optic communication through the single mode fibre is limited by the amplification bandwidth of Er-doped fibres. To increase the capacity of fibre optic communication research community around the world are proposing different approaches. One of them is to use the low loss window (1260-1625nm) of silica optical fibres by developing efficient fibre amplifiers and lasers. Another one is to use novel fibres such as multi-core fibres, multi-mode fibres and multi-element fibres (MEFs) for space division multiplexing in the C-band (1525-1565nm). In this thesis, we developed amplifiers and lasers within the wavelength band from 1150-1625nm using Bi-doped and multi-element Er-doped fibres. Here, we investigated the fabrication of Bi-doped optical fibres in different glass hosts (aluminosilicate and phosphosilicate) using MCVD-solution doping technique. Bi-doped aluminosilicate fibres are used to develop an amplifier with 12dB gain at 1180nm. Bi-doped phosphosilicate fibres are used to develop amplifiers and lasers in the second telecommunication band from 1300-1360nm. An all-fibre Bi-doped phosphosilicate amplifier with a 25dB at gain in a 40nm bandwidth from 1320-1360nm is reported. Also, a Bi-doped fibre laser operating at 1360nm with an output power of 110mW, and a picosecond pulsed mode-locked fibre laser operating at 1340nm with a peak power of 1.15W, are demonstrated. These amplifiers and lasers have important applications in medicine, astronomy and optical fibre communication. In addition, we also discussed the novel fibres known as MEFs and developed core and cladding pumped broadband amplifiers covering 1500-1620nm using multi-element Er and Er/Yb-doped fires, respectively.

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38

Miao, Yingyu. "Advanced overmoded circuits for gyro-amplifiers." College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/1370.

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Thesis (Ph. D.) -- University of Maryland, College Park, 2004.<br>Thesis research directed by: Electrical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

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39

Al-Tahir, Hibah. "Multidimensional Measurements : on RF Power Amplifiers." Thesis, University of Gävle, Department of Technology and Built Environment, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-729.

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<p>Abstract</p><p>In this thesis, a measurement system was set to perform comprehensive measurements on RF power amplifiers. Data obtained from the measurements is then processed mathematically to obtain three dimensional graphs of the basic parameters affected or generated by nonlinearities of the amplifier i.e. gain, efficiency and distortion. Using a class AB amplifier as the DUT, two sets of signals – both swept in power level and frequency - were generated to validate the method, a two-tone signal and a WCDMA signal. The three dimensional plot gives a thorough representation of the behavior of the amplifier in any arbitrary range of spectrum and input level. Sweet spots are consequently easy to detect and analyze. The measurement setup can also yield other three dimensional plots of variations of gain, efficiency or distortion versus frequencies and input levels. Moreover, the measurement tool can be used to plot traditional two dimensional plots such as, input versus gain, frequency versus efficiency etc, making the setup a practical tool for RF amplifiers designers.</p><p>The test signals were generated by computer then sent to a vector signal generator that generates the actual signals fed to the amplifier. The output of the amplifier is fed to a vector signal analyzer then collected by computer to be handled. MATLAB® was used throughout the entire process.</p><p>The distortion considered in the case of the two-tone signals is the third order intermodulation distortion (IM3) whereas Adjacent Channel Power Ratio (ACPR) was considered in the case of WCDMA.</p>

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40

Condo, Neira Edith Graciela. "Multidimensional Measurements on RF Power Amplifiers." Thesis, University of Gävle, Department of Technology and Built Environment, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-804.

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<p>Measurements are important to specify and verify properties for components, modules and systems. The specifications for a certain figure of merit are usually given in a numerical value or a two dimensional plot. However, there are some devices, like power amplifiers with certain figure of merits that depends on two or more working conditions, requiring a three dimensional plot.</p><p>This thesis presents a measurement method including graphical user interface of three parameters gain, efficiency and distortion when two-tone or WCDMA signals are used as an input to the PA.</p>

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41

McRory, John Godfrey. "Stacked GaAs FET RF power amplifiers." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0002/NQ31049.pdf.

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42

Austrin, Lars. "On magnetic amplifiers in aircraft applications." Licentiate thesis, Stockholm : Elektrotekniska system, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4439.

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43

Mahdavi, Sareh. "RF power amplifiers and MEMS varactors." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112576.

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This thesis is concerned with the design and implementation of radio frequency (RF) power amplifiers and micro-electromechanical systems---namely MEMS varactors. This is driven by the many wireless communication systems which are constantly moving towards increased integration, better signal quality, and longer battery life.<br>The power amplifier consumes most of the power in a receiver/transmitter system (transceiver), and its output signal is directly transmitted by the antenna without further modification. Thus, optimizing the PA for low power consumption, increased linearity, and compact integration is highly desirable.<br>Micro-electromechanical systems enable new levels of performance in radio-frequency integrated circuits, which are not readily available via conventional IC technologies. They are good candidates to replace lossy, low Q-factor off-chip components, which have traditionally been used to implement matching networks or output resonator tanks in class AB, class F, or class E power amplifiers. The MEMS technologies also make possible the use of new architectures, with the possibility of flexible re-configurability and tunability for multi-band and/or multi-standard applications.<br>The major effort of this thesis is focused on the design and fabrication of an RF frequency class AB power amplifier in the SiGe BiCMOS 5HP technology, with the capability of being tuned with external MEMS varactors. The latter necessitated the exploration of wide-tuning range MEMS variable capacitors, with prototypes designed and fabricated in the Metal-MUMPS process.<br>An attempt is made to integrate the power amplifier chip and the MEMS die in the same package to provide active tuning of the power amplifier matching network, in order to keep the efficiency of the PA constant for different input power levels and load conditions.<br>Detailed simulation and measurement results for all circuits and MEMS devices are reported and discussed.

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44

Fews, Hayden Scott. "Multiwave mixing in semiconductor optical amplifiers." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300912.

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45

Chestnut, David Alexander. "Fibre lasers and amplifiers with nonlinearity." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410006.

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46

Hall, Fenella T. H. "Mathematical models for class-D amplifiers." Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/11891/.

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We here analyse a number of class-D amplifier topologies. Class-D amplifiers operate by converting an audio input signal into a high-frequency square wave output, whose lower-frequency components can accurately reproduce the input. Their high power efficiency and potential for low distortion makes them suitable for use in a wide variety of electronic devices. By calculating the outputs from a classical class-D design implementing different sampling schemes we demonstrate that a more recent method, called the Fourier transform/Poisson resummation method, has many advantages over the double Fourier series method, which is the traditional technique employed for this analysis. We thereby show that when natural sampling is used the input signal is reproduced exactly in the low-frequency part of the output, with no distortion. Although this is a known result, our calculations present the method and notation that we later develop. The classical class-D design is prone to noise, and therefore negative feedback is often included in the circuit. Subsequently we incorporate the Fourier transform/Poisson resummation method into a formalised and succinct analysis of a first-order negative feedback amplifier. Using perturbation expansions we derive the audio-frequency part of the output, demonstrating that negative feedback introduces undesirable distortion. Here we reveal the next order terms in the output compared with previous work, giving further insight into the nonlinear distortion. We then further extend the analysis to examine two more complex negative feedback topologies, namely a second-order and a derivative negative feedback design. Modelling each of these amplifiers presents an increased challenge due to the differences in their respective circuit designs, and in addition, for the derivative negative feedback amplifier we must consider scaling regimes based on the relative magnitudes of the frequencies involved. For both designs we establish novel expressions for the output, including the most significant distortion terms.

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47

Morley, Richard James. "RF excited CO2 amplifiers for lidar." Thesis, Heriot-Watt University, 1992. http://hdl.handle.net/10399/1484.

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48

Cairns, Gerald Francis. "Development studies of XUV laser amplifiers." Thesis, Queen's University Belfast, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295405.

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49

Zewani, Mohammed. "Low distortion wideband microwave power amplifiers." Thesis, University of Leeds, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.440631.

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50

Yao, Jianguo. "Optical switching using semiconductor laser amplifiers." Thesis, University of Essex, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260402.

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